18174421 has 2 divisors, whose sum is σ = 18174422. Its totient is φ = 18174420.

The previous prime is 18174397. The next prime is 18174449. The reversal of 18174421 is 12447181.

18174421 = 3014² + 3015².

It is an a-pointer prime, because the next prime (18174449) can be obtained adding 18174421 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9090225 + 9084196 = 3015^2 + 3014^2 .

It is a cyclic number.

It is not a de Polignac number, because 18174421 - 2⁷ = 18174293 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18174421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18174461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9087210 + 9087211.

It is an arithmetic number, because the mean of its divisors is an integer number (9087211).

Almost surely, 2^18174421 is an apocalyptic number.

18174421 is the 3015-th centered square number.

It is an amenable number.

18174421 is a deficient number, since it is larger than the sum of its proper divisors (1).

18174421 is an equidigital number, since it uses as much as digits as its factorization.

18174421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1792, while the sum is 28.

The square root of 18174421 is about 4263.1468424158. The cubic root of 18174421 is about 262.9179241447.

The spelling of 18174421 in words is "eighteen million, one hundred seventy-four thousand, four hundred twenty-one".